Contribution of ISAC (CNR) to Micrometeorology Scientific Research at the ATTO Project

The Amazon Tall Tower Observatory (ATTO) is a research infrastructure realized in the Amazon pristine rain forest. The main goal of the project is to measure biological, chemical and meteorological data following a multi-disciplinary, multi-platform, multi-sensor and multi-frequency approach for understanding how the Amazon rainforest interacts with the soil beneath and the atmosphere above. ATTO represents a unique opportunity to learn more about the energy fluxes, the water and biogeochemical cycles above the Amazon Forest and their influence on the global climate. Two towers (80 m and 325 m high) are instrumented with high-vertical resolution sensors for a continuous monitoring of different air layers inside and above the forest. The ATTO towers offer the rare possibility of a direct observation of turbulent quantities and of the atmosphere thermodynamics in the roughness sublayer (RSL) and in the surface layer above it. During night-time the whole boundary layer is lower than the towers. The ISAC (CNR) contributes to the micrometeorology scientific research activity at the ATTO Project following different research topics, all aimed to a better understanding of the flow dynamics in different stability conditions and of the role of turbulent transport in the chemical components above the forest. We will give a brief overview of the main results and of the work in progress relative: to the estimation of the boundary layer height in stable stratification; to the numerical simulations LES (PALM-4U) of the microscale flow above the forest; to the developments of an original theoretical approach based on a cospectral-budget model for the RSL study; to the development of a Lagrangian model that recovers oscillatory correlations of wind components above tall canopies; to the validation of the Relaxed Eddy-Accumulation technique for estimating scalar fluxes for which fast-response gas analyzers are impractical or non-existent (such as methan, isoprene), crucial for understanding the biosphere-atmosphere interaction and its influence on the biodiversity.